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Abstract:

In a prior-art nail puncture test, it has been difficult to measure the
temperature at a short-circuiting portion, which is closely related to
the scale of an accident which occurs. As a solution, A nail puncture
test device having a temperature measurement function, a sheath
thermocouple, and a fixing portion 6 of the sheath thermocouple, wherein
a bottomed hole through which the sheath thermocouple is inserted is
bored in the axial direction from a head portion to the vicinity of the
distal end at the center part of the outer frame, and the sheath
thermocouple is fixed to the outer frame by the fixing portion 6 in a
state where the sheath thermocouple is inserted into the bottomed hole
and the distal end thereof having a temperature measurement point is in
contact with the bottom of the hole is provided.

Claims:

1. A nail puncture test device having a temperature measurement function,
comprising an outer frame 3 made of high-hardness metal or ceramic and
having the external shape of a nail, a sheath thermocouple 4, and a
fixing portion 6 of the sheath thermocouple 4, wherein a bottomed hole 5
into which the sheath thermocouple 4 is inserted is bored in an axial
direction from a head portion to the vicinity of a distal end at a center
part of the outer frame 3, and the sheath thermocouple 4 is fixed to the
outer frame 3 by the fixing portion 6 in a state where the sheath
thermocouple 4 is inserted into the bottomed hole 5 and a distal end
thereof having a temperature measurement point is in contact with the
bottom of the hole.

2. The nail puncture test device having a temperature measurement
function described in claim 1, wherein the fixing portion 6 of the sheath
thermocouple 4 is fixed by silver brazing, fixed by using an elastic
resin plug having the sheath thermocouple 4 inserted through a central
hole thereof as the fixing portion 6 and pressing it into the outer frame
3, or fixed by inorganic cement.

Description:

TECHNICAL FIELD

[0001] The present invention relates to a nail puncture test device having
a temperature measurement function.

BACKGROUND ART

[0002] If electrical short-circuit occurs inside a battery with high
energy density such as a lithium ion battery, abnormal heat generation is
caused depending on the structure, and an accident such as a burn, a fire
or the like can occur.

[0003] Thus, in a battery with high energy density such as a lithium ion
battery, such a test is conducted that the battery is punctured by a nail
made of metal so as to destroy an insulating bulkhead inside and to cause
internal short-circuit and to check that heat generation or ignition
resulting in the accident does not occur. This test is called a nail
puncture test.

Citation List

Patent Literature

[0004] Patent Document 1: Japanese Patent Laid-Open No. 2005-327616

SUMMARY OF INVENTION

Technical Problem

[0005] In the prior-art nail puncture test, as described above, a battery
to be tested is punctured by a nail made of metal so as to cause
short-circuit inside the battery. In this test, in many cases, a
temperature sensor such as a thermocouple is installed on the battery to
be tested in order to measure the amount of heat generated at the time of
short-circuit, but if the sensor is installed inside the battery to be
tested, the sensor itself might become a source of the short-circuit.
Also, since the internal structure of the battery to be tested changes,
an installed position of the temperature sensor is limited to the surface
of the battery or the like. Thus, it has been difficult to measure the
temperature at a short-circuiting portion, which is closely related to
the scale of an accident which occurs.

Solution to Problem

[0006] In order to facilitate measurement of a temperature at a
short-circuiting portion, which is closely related to the scale of the
accident which occurs, the present invention provides a nail puncture
test device having a temperature measurement function, comprising an
outer frame 3 made of a high-hardness metal or ceramic and having the
external shape of a nail, a sheath thermocouple 4, and a fixing portion 6
of the sheath thermocouple 4, wherein a bottomed hole 5 through which the
sheath thermocouple 4 is inserted is bored in an axial direction from a
head portion to the vicinity of a distal end at a center part of the
outer frame 3, and the sheath thermocouple 4 is fixed to the outer frame
3 through the fixing portion 6 in a state where the sheath thermocouple 4
is inserted into the bottomed hole 5 and a distal end thereof having a
temperature measurement point is in contact with the bottom of the hole.

[0007] Also, the present invention is the nail puncture test device having
a temperature measurement function described in claim 1, specifically in
which the fixing portion 6 of the sheath thermocouple 4 is fixed by
silver brazing, fixed by using an elastic resin plug having the sheath
thermocouple 4 inserted through a central hole thereof as the fixing
portion 6 and pressing it into the outer frame 3, or fixed by inorganic
cement.

Advantageous Effects of Invention

[0008] Since the nail and the temperature sensor are constructed
integrally in the present invention which is the nail puncture test
device having a temperature measurement function, comprising the outer
frame 3 made of high-hardness metal or ceramic and having the external
shape of a nail, the sheath thermocouple 4, and the fixing portion 6 of
the sheath thermocouple 4, wherein the bottomed hole 5 into which the
sheath thermocouple 4 is inserted is bored in the axial direction from
the head portion to the vicinity of the distal end at the center part of
the outer frame 3, and the sheath thermocouple 4 is fixed to the outer
frame 3 by the fixing portion 6 in the state where the sheath
thermocouple 4 is inserted into the bottomed hole 5 and the distal end
thereof having a temperature measurement point is in contact with the
bottom of the hole, internal short-circuit in the battery to be tested
can be made to occur and the temperature of the short-circuiting portion
can be measured with only one testing device of the present invention.

[0009] Also, in the present invention, the temperature measurement of the
internal short-circuiting portion of the battery to be tested is made
possible in the nail puncture test by constructing the nail and the
temperature sensor integrally.

[0010] Moreover, in the present invention, since a sheath thermocouple
wire is contained in the sheath through an insulating article, the sheath
thermocouple is not affected by the electric potential of the external
battery to be tested and the electric potential of the outer frame made
of metal. Therefore, the temperature can be accurately measured.

[0011] Furthermore, the sheath thermocouple 4 can be attached in the
bottomed hole 5 reliably and easily since the present invention is a nail
puncture test device having a temperature measurement function described
in claim 1, where the fixing portion 6 of the sheath thermocouple 4 is
fixed by silver brazing, fixed by using an elastic resin plug having the
sheath thermocouple 4 inserted through a central hole thereof as the
fixing portion 6 and pressing it into the outer frame 3, or fixed by
inorganic cement.

BRIEF DESCRIPTION OF DRAWINGS

[0012] FIG. 1 is a longitudinal sectional diagram illustrating a state
where a nail puncture test device of the present invention is inserted
into a battery to be tested.

REFERENCE SIGNS LIST

[0013] 3 outer frame

[0014] 4 sheath thermocouple

[0015] 6 fixing portion

[0016] 5 bottomed hole

[0017] 1 nail puncture test device

DESCRIPTION OF EMBODIMENTS

[0018] The present invention is a nail-shaped test device used for a nail
puncture test, in which a nail and a temperature sensor are constructed
integrally, thus easy measurement of a temperature at a short-circuiting
portion of a battery to be tested, which has been difficult, is enabled.

[0019] FIG. 1 illustrates a sectional structure thereof. Reference numeral
1 denotes a nail puncture test device according to the present invention,
and a dotted line 2 denotes a battery to be tested which is punctured by
the nail puncture test device 1.

[0020] The nail puncture test device 1 is formed of an outer frame 3
having the external shape of a nail, a sheath thermocouple 4, and a
fixing portion 6 of the sheath thermocouple 4, wherein a bottomed hole 5
into which the sheath thermocouple 4 is inserted is bored in the axial
direction from a head portion to the vicinity of the distal end at the
center part of the outer frame 3, and the sheath thermocouple 4 is fixed
to the outer frame 3 by the fixing portion 6 in a state where the sheath
thermocouple 4 is inserted into the bottomed hole 5 and the distal end
thereof having a temperature measurement point is in contact with the
bottom of the hole.

[0021] As the material of the outer frame 3, high-hardness metal or
ceramic is used in order to prevent deformation at puncture.

[0022] Fixing of the sheath thermocouple 4 at the fixing portion 6 may be
fixing by means of silver brazing, fixing by means of using an elastic
resin plug having the sheath thermocouple 4 inserted through a central
hole thereof as the fixing portion 6 and pressing it into the outer frame
3, or fixing by means of inorganic cement.

[0023] The sheath thermocouple 4 contains a pair of thermocouple wires
interposing an inorganic insulating material powder such as magnesia,
alumina, or the like between them inside a metal pipe called sheath, and
the pair of thermocouple wires are bonded inside the sheath distal end to
form the temperature measurement point. Though not shown in FIG. 1, at a
rear end of the sheath thermocouple 4, the thermocouple wires of the
sheath thermocouple 4 and compensating lead wires are connected. The
compensating lead wires are connected to an instrument which converts a
thermoelectromotive force of the sheath thermocouple 4 to a temperature
and records/displays it, and this temperature is the temperature of the
short-circuiting portion in the battery to be tested which is measured by
the sheath thermocouple 4.

[0024] The puncture of the nail puncture test device 1 into the battery 2
to be tested is performed manually by applying an impact to the head
portion by means of a hammer or the like or by applying a downward force
to the head portion by an exclusive device as in the past, and the hammer
or the exclusive device having the shape not interfering with the portion
of the sheath thermocouple 4 outside the outer frame 3 made of metal is
used.

EXAMPLE 1

[0025] According to FIG. 1, an example of the nail puncture test device 1
according to the present invention will be described below.

[0026] The outer frame 3 is made of high-hardness high-speed steel SKH51
in order to prevent deformation at puncture and to allow repeated use.
The shape has a puncturing-part outer diameter of Φ2.5 mm, a
head-portion outer diameter of Φ8.0 mm, an apex angle of a distal-end
conical part of 30°, a length from the head portion to the distal
end of 42 mm, and a diameter of the sheath thermocouple insertion hole 5
of 0.35 mm.

[0027] The sheath thermocouple 4 having the sheath material of NCF 600, a
sheath outer diameter of Φ0.3 mm, and a thermocouple wire of K type
is used.

[0028] Also, the fixing portion 6 of the sheath thermocouple 4 to the
outer frame 3, made of metal, is fixed by silver brazing.

[0029] It was confirmed that by means of the nail puncture test device 1,
occurrence of short-circuit inside the battery to be tested and accurate
measurement of the temperature at the short-circuiting portion can be
repeatedly performed.

INDUSTRIAL APPLICABILITY

[0030] The present invention is a nail puncture test device to puncture
the battery to be tested and can be used for a subject to be tested whose
internal structure changes.